Injector apparatuses of this nature already exist, for example, as described in German Pat. No. 3 330 772, in which the pilot injection and main injection sequences are fixed once and for all by construction and cannot be modified while the engine is operating. As a result, optimization performed for any given engine operating range is poorly adapted to other ranges, and there is no way of switching off the pilot injection stage or the main injection stage.
An aim of the present invention is to remedy these drawbacks by providing an injector apparatus capable of adjusting the beginnings and the durations of the main injection stages and of the pilot injection stages, regardless of the type of main injection fuel, i.e. regardless of whether it is a liquid or a gas.